Adjustable weight distribution for drone

ABSTRACT

Apparatus, methods, and systems for adjusting a center of mass of a drone may include a balance track and a repositionable weight. The balance track may extend outwardly from a central region of the drone. The balance track may include a plurality of weight-balance fixation positions. The repositionable weight may be configured to be secured at any one of the plurality of weight-balance fixation positions. Various embodiments may include receiving a weight-distribution input relating to balancing the drone. A weight-distribution balance profile may be determined, based on the weight-distribution input, for determining whether a repositionable weight should be repositioned among a plurality of weight-balance fixation positions on a balance track extending outwardly from a central region of the drone. The repositionable weight may be repositioned according to the weight-distribution balance profile.

BACKGROUND

A multi-rotor helicopter drone (referred to herein as a “drone”) is anunmanned aerial vehicle that uses a plurality of powered rotors for liftand propulsion. For example, a quad-copter, also called a quad-rotorhelicopter or quad-rotor, is a drone that uses four powered rotors forlift and propulsion. Similarly, an octo-copter includes eight poweredrotors. As with most aerial vehicles, drones are generally balanced toprovide orientation stability while the rotor speeds are varied tomaintain a desired orientation (i.e., roll, pitch, or yaw). Balancingthe airframe of the drone is important because if the drone is out ofbalance, the rotors may expend more energy just to maintain levelflight. However, small adjustments or additions to the airframe of thedrone (e.g., added payload or components, like a camera or lens) canchange the weight distribution and cause the airframe to be out ofbalance.

SUMMARY

Various embodiments include a weight distribution apparatus foradjusting a center of mass of a drone, such as a multi-rotor helicopterdrone, including a first balance track and a repositionable weight. Thefirst balance track may extend outwardly from a central region of thedrone. The first balance track may include a plurality of weight-balancefixation positions. The repositionable weight may be configured to besecured at any one of the plurality of weight-balance fixationpositions.

In various embodiments, the repositionable weight may be slidable alongthe first balance track between the plurality of weight-balance fixationpositions. The first balance track may be disposed on an extension armof the drone. The extension arm may extend laterally from the centralregion, with a distal end of the extension arm supporting an airpropulsion unit. The repositionable weight may wrap around at least aportion of the extension arm using an essential structural shape of theextension arm as the first balance track. The plurality ofweight-balance fixation positions may include a series of aperturesextending through the extension arm. The repositionable weight may beconfigured to ride along guide elements included on the first balancetrack. The repositionable weight may include an electronic component,such as an energy cell, an actuator, an indicator, a circuit element, asensor, and/or a camera. The weight distribution apparatus may alsoinclude a control unit configured to activate the electronic component.The control unit may be fixed to the repositionable weight. The controlunit may be configured to activate the electronic component, such aswhen the control unit is remote from the repositionable weight. Thecontrol unit may be configured to activate the electronic component. Inaddition, the control unit may include a radio frequency transceiver anda processor coupled to the radio frequency transceiver. The processormay be configured with processor-executable instructions to activate amovement of the repositionable weight from a first one of the pluralityof weight-balance fixation positions to a second one of the plurality ofweight-balance fixation positions in response to receiving an activationsignal via the radio frequency transceiver.

In various embodiments, the repositionable weight may be removablysecured to at least one of the plurality of weight-balance fixationpositions. The plurality of weight-balance fixation positions may beevenly distributed along a longitudinal extent of the first balancetrack. In addition, a second balance track may extend outwardly from thecentral region along a second axis that may be different from a firstaxis of the first balance track. The first axis may intersect the secondaxis at a non-orthogonal angle. Further, a third balance track mayextend away from the central region along a third axis that may bedifferent from both the first axis and the second axis. The first axismay be parallel to the second axis. Also, the first and second axes maynot be parallel to extension arms supporting rotors of the drone. Thefirst balance track may be configured to change length for changing therepositionable weight from a first one of the plurality ofweight-balance fixation positions to a second one of the plurality ofweight-balance fixation positions. The first balance track may beconfigured to rotate about a vertical central axis of the drone. Inresponse to a change in a weight-distribution balance profile of thedrone, in which a payload is added to or removed from the drone, theplurality of weight-balance fixation positions may be arranged such thatthe repositionable weight may be repositioned to a different one of theplurality of weight-balance fixation positions in order to restore theweight-distribution balance profile. The plurality of weight-balancefixation positions may be arranged such that changing the repositionableweight from a first one of the plurality of weight-balance fixationpositions to a second one of the plurality of weight-balance fixationpositions may change the center of mass of the drone.

Various embodiments may further include a method of adjusting a centerof mass of a drone using a weight distribution apparatus. The method mayinclude receiving a weight-distribution input relating to balancing themulti-rotor helicopter drone. In addition, a processor may determine aweight-distribution balance profile based on the weight-distributioninput. The processor may also determine whether a first repositionableweight should be repositioned. A signal may be output in response todetermining that the first repositionable weight should be repositionedon the first balance track according to the weight-distribution balanceprofile.

In various embodiments, the signal may be used to reposition the firstrepositionable weight in a variety of ways. In some embodiments, thesignal may cause an actuator to release the first repositionable weightfor removal from a first balance track in order to conform to theweight-distribution balance profile. In some embodiments, the signal maycause an actuator to move the first repositionable weight along a firstbalance track between a plurality of weight-balance fixation positions.In some embodiments, the signal may cause the actuator to rotate thefirst balance track about a vertical central axis of the drone in orderto change the first repositionable weight from a first one of aplurality of weight-balance fixation positions to a second one of theplurality of weight-balance fixation positions. The signal may cause theactuator to rotate the first balance track to propel the drone withdirect engagement along a surface.

In some embodiments, the weight-distribution input may be received froma remote source. In some embodiments, the signal may cause an indicatorto indicate that the first repositionable weight should be repositioned.In some embodiments, the signal may cause an indicator to indicate thatthe first repositionable weight should be moved along a first balancetrack between a plurality of weight-balance fixation positions. In someembodiments, the signal may cause an indicator to indicate that thefirst repositionable weight should be removed from a first balance trackin order to conform to the weight-distribution balance profile. In someembodiments, the signal may cause an indicator to indicate that a secondrepositionable weight should be added in order to conform to theweight-distribution balance profile. In some embodiments, the signal maycause an indicator to indicate that a length of a first balance trackshould be changed in order to change the first repositionable weightfrom a first one of a plurality of weight-balance fixation positions toa second one of the plurality of weight-balance fixation positions. Insome embodiments, the signal may cause an indicator to indicate that afirst balance track should be rotated about a vertical central axis ofthe drone in order to change the first repositionable weight from afirst one of a plurality of weight-balance fixation positions to asecond one of the plurality of weight-balance fixation positions. Insome embodiments, the indicator may be on the drone and/or remote fromthe drone.

In various embodiments, the method may further include repositioning aposition of the first repositionable weight may be changed among theplurality of weight-balance fixation positions on a first balance trackextending outwardly from a central region of the drone. Repositioningthe position of the first repositionable weight may be in response todetermining that the first repositionable weight should be repositioned.Repositioning the repositionable weight to a different one of theplurality of weight-balance fixation positions may be in response to achange in a weight-distribution balance profile of the drone from apayload being added to or removed from the drone. The plurality ofweight-balance fixation positions may be arranged such thatrepositioning the repositionable weight restores the weight-distributionbalance profile. The repositionable weight may be repositioned from afirst one of the plurality of weight-balance fixation positions to asecond one of the plurality of weight-balance fixation positions. Theplurality of weight-balance fixation positions may be arranged such thatrepositioning the repositionable weight changes the center of mass ofthe drone. The first repositionable weight may be a payload temporarilycarried by the drone.

Various embodiments may include a drone having a processor configuredwith instructions for performing operations corresponding to one or moreembodiment methods. Various embodiments may further include a drone withmeans for performing operations corresponding to one or more embodimentmethods described herein. The various embodiments may further include anon-transitory computer readable medium having instructions configuredto cause a processor to perform operations corresponding to one or moreembodiment methods described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments, andtogether with the general description given above and the detaileddescription given below, serve to explain the features of the variousembodiments.

FIG. 1A shows a perspective view of a drone according to variousembodiments.

FIG. 1B is a cross-sectional view of the drone of FIG. 1A at 1B-1Baccording to various embodiments.

FIG. 2A is an isolated view of an extension arm with a weightdistribution apparatus according to various embodiments.

FIG. 2B is a cross-sectional view the extension arm of FIG. 2A at 2B-2Baccording to various embodiments.

FIG. 3 is a top view of a drone and a schematic relief diagram of acontrol unit and remote communication device according to variousembodiments.

FIG. 4 is a cross-sectional view of a weight distribution apparatusaccording to various embodiments.

FIG. 5A is an isolated view of an extension arm with a weightdistribution apparatus according to various embodiments.

FIG. 5B is a cross-sectional view of the extension arm of FIG. 5A at5B-5B according to various embodiments.

FIG. 6A is an isolated view of an extension arm with a weightdistribution apparatus according to various embodiments.

FIG. 6B is a cross-sectional view of the extension arm of FIG. 6A at6B-6B according to various embodiments.

FIG. 7 is a top view of a quad-copter drone with extension armsintersecting non-orthogonally according to various embodiments.

FIG. 8 is a top view of a tri-copter drone with extension arms accordingto various embodiments.

FIG. 9 is a top view of an octo-copter drone with extension armsaccording to various embodiments.

FIG. 10 is a top view of an H-frame quad-copter drone with extensionarms extending parallel to one another according to various embodiments.

FIG. 11 is a perspective view of a drone including balancing tracks fora weight distribution apparatus offset from propulsion-unit extensionarms according to various embodiments.

FIG. 12 is a perspective view of a drone includingretractable/extendable balance tracks according to various embodiments.

FIG. 13A is a perspective view of a drone including rotating balancingtracks according to various embodiments.

FIG. 13B is a side view of the drone in FIG. 13A according to variousembodiments.

FIG. 14A is a process flow diagram illustrating an embodiment method foradjusting a center of mass of a drone according to various embodiments.

FIG. 14B is a process flow diagram illustrating another embodimentmethod for adjusting a center of mass of a drone according to variousembodiments.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.References made to particular examples and implementations are forillustrative purposes, and are not intended to limit the scope of theclaims.

Various embodiments include a weight distribution apparatus, system,and/or method for adjusting a center of mass of a drone, such as amulti-rotor helicopter drone. The combined weights of the multi-rotorhelicopter drone, including any payload, may be taken into account toachieve a desired center of mass for the combined masses. In accordancewith various embodiments, the center of mass of the drone may beadjusted using one or more balance tracks extending outwardly from acentral region of the drone. The balance tracks may each include aplurality of weight-balance fixation positions configured to receive arepositionable weight for achieving the desired center of mass. Therepositionable weights, when positioned in an appropriate weight-balancefixation position, may balance the drone to compensate for imbalancesfrom payloads, such as temporarily transported packages for newly addedcomponents. In this way, balance may be achieved despite the removal ofpayload(s) or the addition of new, unusual, or different payloads.

In various embodiments, a payload carried by the drone, such as acomponent having a purpose other than to balance the drone, may be usedas the repositionable weights. The drone may be re-balanced by changinga position of the payload or a payload attachment tether to a selectedweight-balance fixation position. Using the payload as therepositionable weight eliminates or minimizes the need for added weightthat serves no purpose other than to balance the drone.

The terms “multi-rotor helicopter drone” and “drone” are usedinterchangeably herein to refer to an unmanned aerial vehicle. A dronemay generally be configured to fly autonomously, semi-autonomously, orcontrolled wirelessly by a remote piloting system that is automatedand/or manually controlled. A drone may be propelled for flight in anyof a number of known ways. For example, a plurality of propulsion units,each including one or more propellers, may provide propulsion or liftingforces for the drone and any payload carried by the drone. One or moretypes of power source, such as electrical, chemical, electro-chemical,or other power reserve may power the propulsion units.

As used herein, the terms “center of mass” refer to the point in, on, ornear the drone at which the whole mass of the drone, including thepayload, may be considered as concentrated. A change in the center ofmass of the drone may provide balance, which may equate to stabilityand/or increased efficiency powering propulsion units in flight.

As used herein, the term “payload” refers to any load carried by thedrone that may be removed from or repositioned on the drone. Payload mayinclude things that are carried by the drone, including instruments(e.g., cameras, sensors, etc.), components, and packages. Payload mayinclude temporary items, such as packages, that are carried by the dronefor a limited duration. In addition, payload may include long-term orpermanent items necessary for the operation of the drone. Payloads maybe directly attached to the airframe, such as via a payload attachmentfixture, or carried beneath the airframe on a tether.

As used herein, the term “actuator” refers to a mechanical device thatconverts energy into motion, by which a control system may act upon anenvironment. The source of energy may be, for example, an electriccurrent, hydraulic fluid pressure, pneumatic pressure, mechanicalenergy, thermal energy, or magnetic energy. For example, an electricmotor assembly may be a type of actuator that converts electric currentinto a rotary motion, and may further convert the rotary motion into alinear motion to execute movement. In this way, an actuator may includea motor, gear, linkage, wheel, screw, pump, piston, switch, servo, orother element for converting one form of energy into motion.

Various embodiments may be implemented on different types of multi-rotorhelicopter drones, such as a quad-copter drone 10 illustrated in FIG.1A. The drone 10 may include a weight distribution apparatus 100 foradjusting a center of mass thereof. The drone 10 may include a frame 110and a plurality of air propulsion units 120 supported on extension arms130. FIG. 1A illustrates four air propulsion units 120, each mounted ona distal end 139 of a separate extension arm 130. Each of the airpropulsion units 120 may include a propeller 125. The air propulsionunits 120 may collectively provide vertical and/or horizontalpropulsion. In addition, varying levels of power may be supplied toindividual air propulsion units 120 for controlling stability andmaneuverability during take-off, landing, and in flight. The frame 110may also support various other components (not shown), includingcontrols, actuators, power sources, cameras/sensors, circuit elements,and communication systems.

The drone 10 may generally fly in any unobstructed horizontal andvertical direction or may hover in one place. In addition, the drone 10may be configured with processing and communication devices that enablethe drone 10 to navigate, such as by controlling the air propulsionunits 120 to achieve flight directionality and to receive positioninformation and information from other system components includingvehicle systems, package delivery service servers and so on. Theposition information may be associated with the current position of thedrone 10 and the location of the delivery or other destination.

For ease of description and illustration, some details of the drone 10are omitted, such as wiring, frame structure interconnects or otherfeatures that would be known to one of skill in the art. For example,while the drone 10 is described as having extension arms 130 secured tothe frame 110, a drone may be constructed with a frame integrally formedwith the extension arms 130. In various embodiments, the drone 10includes four air propulsion units 120, but more or fewer air propulsionunits 120 may be used.

In various embodiments, the drone 10 may include the weight distributionapparatus 100 for adjusting a center of mass of the drone 10. In someembodiments, the weight distribution apparatus 100 may include a balancetrack 140 configured to receive a repositionable weight 150 foradjusting the center of mass. The balance track 140 may extend laterallyaway from a central portion 115 of the frame 110. In addition, thebalance track 140 may include a plurality of weight-balance fixationpositions 145 spaced apart along a longitudinal extent of the balancetrack 140. Each of the weight-balance fixation positions 145 may bedisposed a different horizontal distance from a center (e.g., center ofthe central portion 115) of the drone 10. Each repositionable weight 150provides a weight force acting on the balance track 140 at theweight-balance fixation position 145 in which it is secured. Inparticular, a center of mass of each repositionable weight 150 may beconfigured to provide the weight force at a precise load locationrelative to the weight-balance fixation position 145 (e.g., a center ofeach weight-balance fixation position 145). A distance from the centerof the drone 10 to the precise load location, multiplied by the weightof the repositionable weight 150, equals a rotational balancing force,in a pitch or yaw direction, provided by the repositionable weight 150.In this way, the weight-balance fixation positions 145 disposed closerto the central portion 115 (i.e., closer to a proximal end 131 of theextension arm 130) are associated with smaller rotational balancingforces than the weight-balance fixation positions 145 disposed furthestfrom the central portion 115 (i.e., closer to the distal end 139 of theextension arm 130). Both the weight of the repositionable weight 150 andthe weight-balance fixation positions 145 to which the repositionableweight 150 is attached or otherwise coupled may be selected based on theamount of balancing force needed to offset imbalances in the frame 110,such as from an attached payload 50. In other words, securing therepositionable weight 150 in one of the weight-balance fixationpositions 145 shifts the center of mass of the drone 10 by adeterminable amount. The weight-balance fixation positions 145 areillustrated as being evenly spaced, but other spacing may be used. Forexample, the spacing may incrementally get smaller or greater along anextent of the balance track 140.

By including more than one balance track 140 extending in differentdirections from the central portion 115, the weight distributionapparatus 100 may enable adjustment of the center of mass along twoaxes. Individual repositionable weights 150 on different balance tracks140 may be placed (e.g., removably secured) at different distances fromthe central portion 115 in order to balance the drone 10.

The repositionable weights 150 may be removably secured, meaning thatthe repositionable weights 150 may each be separately attached to thebalance track 140, but subsequently removed from the balance track 140for repositioning the weights. In addition, in order to conform to adetermined weight-distribution profile, one or more of therepositionable weights 150 may be removed from the balance track 140,and not repositioned thereon.

The drone 10 may include pairs of the balance tracks 140 extending inopposite directions from the central portion 115 and along alongitudinal axis 135 (indicated as double-headed arrows in FIG. 1A)common to both balance tracks 140. One of the longitudinal axes 135 of afirst pair of extension arms 130 may extend perpendicular to another oneof the longitudinal axis 135 of a second pair of the extension arms 130.

The frame 110 may also carry a payload 50 (e.g., one or more packages),using package securing elements, such as fasteners or a suitablecompartment (not shown). The drone 10 may be equipped with apackage-securing unit (not shown), such as a gripping and releasemechanism, with a motor and so on, configured to at least temporarilygrasp and hold the payload 50. The payload 50 may be a single unitaryelement or multiple elements grouped together or separately. Inaddition, the payload 50 may be one or more packages or componentscarried by the drone 10 on a short-term basis, long-term basis,permanently, or some combination thereof. While the payload 50 isillustrated in FIG. 1A as being attached in the central portion 115underneath the frame 110, the payload may alternatively be attached atopthe frame 110 or any other suitable location. Also, the payload 50 maybe attached via a tether connected to an attachment structure or winchinstead of directly to the frame 110.

FIG. 1B is a cross-sectional view of the balance track 140 atcross-section 1B-1B in FIG. 1A illustrating the balance track 140, whichis an integral part of the structure of the extension arm 130,supporting the repositionable weight 150 according to some embodiments.With reference to FIGS. 1A and 1B, the structure of the extension arm130 may form all or part of the balance track 140 and/or the pluralityof weight-balance fixation positions 145. For example, the structure ofthe extension arm 130 may include structural shape that lends rigidityto the arm, such as a T-beam or I-beam cross-section. A part of thestructure of the extension arm 130 may be used as the balance track 140.In addition, a series of apertures may be formed in the extension arm130 for reducing weight or providing other structural or aeronauticalcharacteristics. Those same apertures may be used as the plurality ofweight-balance fixation positions 145.

In some embodiments (e.g., FIG. 1B), the repositionable weight 150 wrapscompletely around the extension arm 130, like a sleeve surrounding asegment of the extension arm 130. In such embodiments, therepositionable weight 150 may include an interior passage 152 with across-sectional shape that matches a portion of the balance track 140for guiding the repositionable weight along the balance track 140. Inthis way, the repositionable weight 150 may not be easily separated fromthe drone 10. The repositionable weight 150 may include a portion thatseparates for removing the repositionable weight 150 from the extensionarm 130. Alternatively, the repositionable weight 150 need not wrap allthe way around the extension arm 130, but just enough to guide and/orensure the repositionable weight 150 does not separate from the balancetrack 140 (i.e., the extension arm).

The repositionable weight 150 may be removably secured to the balancetrack 140 and selectively released for manually moving to a differentposition along the balance track 140. Once secured to the balance track140, the repositionable weight 150 may remain fixed in at least one ofthe plurality of weight-balance fixation positions 145.

A fastener 160 may maintain the repositionable weight 150 in aparticular one of the plurality of weight-balance fixation positions145. For example, the fastener 160 may include a spring 167 that biasesa ball 165 toward the extension arm 130. In this example structure, whenthe ball 165 is aligned with one of the apertures forming theweight-balance fixation positions 145, the ball 165 may be at leastpartially seated within that aligned aperture. The spring 167 may beselected to provide a suitable biasing force in order to hold the ball165 in the aligned aperture and thereby hold in-place the repositionableweight 150. The biasing force may also be light enough that a manualsliding of the repositionable weight 150 along the extension arm willforce the ball 165 out of the aligned aperture and allow therepositionable weight 150 to be moved to a different one of theweight-balance fixation positions 145. Alternatively, the repositionableweight 150 may have a button or aperture for pushing the ball 165against the spring, which pushes the ball 165 out of the alignedaperture, freeing the repositionable weight 150 to move along theextension arm 130. In this way, when the fastener 160 is retracted therepositionable weight 150 is released to move along the balance track140.

The fastener 160 is merely one type of fastener and other fasteners maybe used. For example, a nut and bolt, screw, locking pin, or otherfastener may be employed to removably secure the repositionable weight150 in a select weight-balance fixation position. In addition, thefastener 160 may be a manually adjusted element, an electro-mechanicalelement controlled by a circuit or processor, or a combination thereof.

With the fastener 160 retracted, the repositionable weight 150 may bereleased from one of the plurality of weight-balance fixation positions145 for repositioning to another (e.g., along the longitudinal axis 135in FIG. 1A). The repositionable weight 150 may be configured to slidealong the balance track 140 between the plurality of weight-balancefixation positions 145. Each of the repositionable weights 150 may bemoveable toward or away from the central portion of the frame (e.g.,115) along the balance track 140. Internal surfaces of therepositionable weight 150 may be designed to have a low coefficient offriction in order to promote smooth movement along the balance track140. Alternatively, the repositionable weight 150 and/or the balancetrack 140 may include rollers or ball bearings for reducing friction.

FIG. 2A is an isolated perspective view of a weight distributionapparatus 200 for adjusting a center of mass of a drone (e.g., 10 inFIG. 1A) according to various embodiments. With reference to FIGS.1A-2A, in various embodiments, the weight distribution apparatus 200 mayinclude a balance track 240 for holding a repositionable weight 250 inone or more of a plurality of weight-balance fixation positions. Thebalance track 240 may be attached to and disposed on one of theextension arms 130, which supports a single one of the air propulsionunits 120 of a drone (e.g., 10). The balance track 240, as well as theextension arm 130, may extend laterally from the proximal end 131adjacent the central region (e.g., 115) to the distal end 139 adjacentthe air propulsion unit 120. In addition, the balance track 240 may beone of multiple such balance tracks, each extending laterally onseparate extension arms 130.

The balance track 240 may be formed as a rail assembly with parallelguide elements 242 and crossbars 245. The repositionable weight 250 mayride along the parallel guide elements 242. In some embodiments, therepositionable weight 150 may be positioned anywhere along the balancetrack 240 providing an almost infinite number of weight-balance fixationpositions. The repositionable weight 250 may be removably secured to thebalance track 240 at a particular location by a locking pin or strap(not shown). Alternatively, a gear or wheel assembly of therepositionable weight 250 may be lockable in order to keep therepositionable weight 250 from changing positions along the balancetrack 240. Alternatively, a brake element (not shown) on therepositionable weight 250 may hold onto or engage the crossbars 245 thatserve to define the weight-balance fixation positions. In this way, therepositionable weight 250 may be positioned anywhere along the balancetrack 240 to adjust the overall balance or center of gravity of thedrone.

In some embodiments, the repositionable weight 250 may include anindicator 256 for providing an indication that the repositionable weight250 should or should not be repositioned. For example, the indicator 256may provide a visual indication that suggests a direction therepositionable weight 250 should be moved (e.g., an arrow pointing in adirection). Alternatively or additionally, the indicator 256 may providean audible indication (i.e., sound). Another indicator, which may besimilar to the indicator 256, may optionally be disposed on the balancetrack 240, the extension arm 130, and/or another component.

FIG. 2B is a cross-sectional view at cross-section 2B-2B in FIG. 2A,illustrating the balance track 240 on the extension arm 130, supportingthe repositionable weight 250 according to an embodiment. With referenceto FIGS. 1A-2B, in various embodiments, the repositionable weight 250may include a rail-support assembly 252, such as an actuator,rail-wheels, or glide elements. In addition, the repositionable weight250 may include a control unit 255 for controlling the movement orfixation of the repositionable weight 250 through the rail-supportassembly 252. Optionally, the control unit 255 may include or be coupledto one or more radio frequency transceivers (e.g., Peanut, Bluetooth,Bluetooth LE, Zigbee, Wi-Fi, RF radio, etc.) and an onboard antenna 257for sending and receiving communications, coupled to a processor (e.g.,320 in FIG. 3). For example, the onboard antenna 257 may receive controlsignals for activating and/or controlling the control unit 255. Inaddition or alternatively, the onboard antenna 257 may transmit statusinformation about the repositionable weight 250 or other data, such asinformation collected by an onboard sensor. As a further alternative,the control unit 255 may output a signal to the indicator 256 or thelike to indicate that the repositionable weight 250 should or should notbe moved along the balance track 240.

FIG. 3 is a top view of the drone 10, with a schematic diagram of thecontrol unit 255 and a remote communication device 300 according tovarious embodiments. With reference to FIGS. 1A-3, in variousembodiments, the control unit 255 may be located in one or more of therepositionable weights (e.g., 150 in FIGS. 1A-1B or 250 in FIGS. 2A-2B)and/or another portion of the drone 10 (e.g., the central portion 115).

The control unit 255 may include a power module 310, the processor 320,and a radio frequency (RF) module 330. The processor 320 may include amemory 321 and sufficient processing power to conduct various controland computing operations for controlling the repositionable weights(e.g., 150, 250) and/or a component part thereof. The processor 320 maybe powered from the power module 310, a power source outside the controlunit 255, or a combination thereof. The processor 320 may be one or moremulti-core integrated circuits designated for general or specificprocessing tasks. The memory 321 may be volatile or non-volatile memory,and may also be secure and/or encrypted memory, or unsecure and/orunencrypted memory, or any combination thereof. In other embodiments(not shown), the control unit 255 may also be coupled to an externalmemory, such as an external hard drive.

The processor 320 may communicate with the remote communication device300 through the RF module 330. The onboard antenna 257 may be used toestablish a wireless link 355 (e.g., a bi-directional or unidirectionallink) to a remote antenna 357 of the remote communication device 300.The remote communication device 300 may be a device located elsewhere onthe drone 10 (e.g., the central portion 115 or in another repositionableweight) or remote from the drone 10. The RF module 330 may supportcommunications with multiple ones of the remote communication devices300. While various components (e.g., the power module 310, the processor320, or the RF module 330) of the control unit 255 are shown as separatecomponents, in some embodiments, some or all of the components may beintegrated together in a single device, chip, circuit board, orsystem-on-chip.

In some embodiments, the control unit 255 may be equipped with an inputmodule 340, which may be used for a variety of applications. Forexample, the input module 340 may receive images or data from an onboardcamera or sensor, or may receive electronic signals from othercomponents (e.g., the payload 50). The input module 340 may receive anactivation signal for causing actuators on the drone (e.g., activatingthe motor assembly 567 in FIG. 5B) to reposition the repositionableweight (e.g., 150 in FIGS. 1A-1B or 250 in FIGS. 2A-2B). In addition,the control unit 255 may include an output module 345. The output module345 may be used to activate components (e.g., an energy cell, anactuator, an indicator, a circuit element, a sensor, and/or a camera)that are configured to be used as the repositionable weight and/ortransfer data. Components activated by the output module 345 may beconfigured to be used as the repositionable weight, be disposedelsewhere on the drone 10, or disposed remote from the drone 10. Forexample, the output module 345 may control the rail-support assembly(e.g., 252 in FIG. 2B) for controlling the movement or fixation of therepositionable weight. In this way, one or more components may beconfigured to be repositionable so a mass of each component may be usedto balance the drone 10.

In various embodiments, the drone 10 may be configured to automaticallyadjust a weight distribution. For example, the control unit 255, throughthe input module 340, may receive an input indicating the drone 10 isout-of-balance. The input may include sufficient information for theprocessor 320 to determine a weight-distribution profile and/or whetherto reposition a repositionable weight. In addition, the processor 320may determine where to reposition the repositionable weight in order toinitially balance or restore balance to the drone 10, such as when apayload has been added, removed, and/or moved. In response todetermining that the repositionable weight should be repositioned, theprocessor 320 may output a weight-adjustment signal, such as throughoutput module 345 for adjusting the weight distribution. For example,the weight-adjustment signal may cause motors to move one or morerepositionable weights. In addition, the drone 10 may include multipleones of the processor 320, each controlling a separate repositionableweight, but working together to balance the drone 10.

In various embodiments, the control unit 255 may receive remoteinstructions, such as through the RF module 330, for dynamicallyadjusting the weight distribution. For example, the remote communicationdevice may transmit instructions to or otherwise communicate with thecontrol unit 255. In this way, the remote communication device 300 mayinclude or be coupled to a remote processor 302 configured to determinethe weight-distribution profile and/or whether the repositionable weightshould be repositioned. For example, the remote communication device 300may be a computing device (e.g., cellular telephones, smart phones,laptop computers, tablet computers, smart books, palm-top computers,personal or mobile multi-media players, personal data assistants(PDA's), and similar electronic devices, etc.) and/or be coupled aremote computing device including another remote processor. In responseto determining that the repositionable weight should be repositioned,the remote processor 302 may output a signal that may be transmitted,such as via the wireless link 355, to the processor 320 onboard thedrone 10. This signal may cause the processor 320 onboard the drone 10to output a weight-adjustment signal, such as through an output module345, for adjusting the weight distribution. In addition, the drone 10may include multiple ones of the control unit 255, each controlling aseparate repositionable weight, but working together to balance thedrone 10. Alternatively, the remote processor 302 and the processor 320onboard the drone 10 may share in making determinations, such as thosedescribed.

FIG. 4 is a cross-sectional view, similar to the view shown in FIG. 2B,illustrating a weight distribution apparatus 400 for adjusting a centerof mass of a drone (e.g., 10 in FIGS. 1A and 3) according to variousembodiments. With reference to FIGS. 1A-4, in various embodiments, theweight distribution apparatus 400 may include a repositionable weight450, including side brackets 452 for guiding and maintaining therepositionable weight 450 on the balance track 440. The balance track440 may be one of multiple such balance tracks, each extending laterallyon separate extension arms 130 (e.g., see FIGS. 1A and 3).

FIG. 5A is a perspective view of a weight distribution apparatus 500 foradjusting a center of mass of a drone (e.g., 10 in FIGS. 1A and 3)according to various embodiments. With reference to FIGS. 1A-5A, invarious embodiments, the weight distribution apparatus 500 may include abalance track 540 for holding a repositionable weight 550 in one or moreof a plurality of weight-balance fixation positions 545. The balancetrack 540 may be included as part of, attached to, or disposed on one ofthe extension arms 130, which supports a single one of the airpropulsion units 120 of a drone (e.g., 10 in FIG. 1A). The balance track540, as well as the extension arm 130, may extend laterally from thecentral region (e.g., 115 in FIG. 1A) of the drone toward the airpropulsion unit 120. The balance track 540 may be one of multiple suchbalance tracks, each extending laterally on separate extension arms 130(e.g., see FIGS. 1A and 3).

The repositionable weight 550 may be or include an electronic component570 of the drone. In this way, the repositionable weight 550 may beconfigured to perform functions in addition to adjusting the center ofmass of the drone. For example, the electronic component 570 may includea camera, a sensor, an actuator, an indicator, and/or an energy cell. Inaddition, the electronic component 570 may supply power, such as in thecase of the electronic component 570 being an energy cell, and/or drawpower, such as in the case of the electronic component 570 being acamera, sensor, actuator, or indicator. As a power supply, a conductivestrip 575 may couple the electronic component 570 to other components ofthe drone. The conductive strip 575 may extend along the balance track540 so that the repositionable weight 550 may remain coupled to theconductive strip 575 in any of the plurality of weight-balance fixationpositions 545. In this way, remote elements such as the air propulsionunit 120 or other components may receive power from the electroniccomponent 570 via the conductive strip 575. Alternatively oradditionally, the conductive strip 575 may supply power to theelectronic component 570. In this way, the conductive strip 575 maypower, partially or exclusively, the electronic component 570.

FIG. 5B is a cross-sectional view at cross-section 5B-5B in FIG. 5A,illustrating the balance track 540 on the extension arm 130, supportingthe repositionable weight 550 according to an embodiment. With referenceto FIGS. 1A-5B, in some embodiments, the repositionable weight 550 mayinclude an actuator, such as a motor assembly 567 and an advancementmechanism 565, for removably securing the repositionable weight 550 tothe balance track 540 and/or repositioning the repositionable weight 550along the balance track 540. The motor assembly 567 may control theadvancement mechanism 565 for moving the repositionable weight 550 orholding in-place the repositionable weight 550 at a particular one ofthe plurality of weight-balance fixation positions 545. The advancementmechanism 565 may include a moveable arm, pins, or gears configured tograb hold of the extension arm 130 or balance track 140 for movement.For example, the advancement mechanism 565 may move while leveraging anedge of the apertures forming the plurality of weight-balance fixationpositions 545 for movement. Similarly, the advancement mechanism 565 maylock and thus hold the repositionable weight 550 in a particularposition. In this way, the motor assembly 567 may slide therepositionable weight 550 along the balance track 540. Alternatively,from a locked configuration, the advancement mechanism 565 may beactuated in a way that releases the repositionable weight 550 from beingheld in the particular one of the plurality of weight-balance fixationpositions 545 for manual repositioning or movement by other means.

The motor assembly 567 and/or any other electronic component on therepositionable weight 550 (e.g., the electronic component 570 in FIG.5A) may be activated manually and/or activated by a controller (e.g.,the control unit 255 in FIG. 2B). In addition, the activation of themotor assembly 567 or any other electronic component may be from aswitch or controller that is located either locally on therepositionable weight 550 or remotely. For example, a local switch mayinclude a button on the repositionable weight 550 for activating themotor assembly 567. Similarly, located on or in the repositionableweight 550, the control unit (e.g., 255 in FIG. 2B) with a processor maybe configured with processor-executable instructions to performoperations, such as causing the motor assembly 567 to reposition therepositionable weight 550. Further, the control unit may receive inputfrom a remote source elsewhere on the drone or through wirelesscommunications (e.g., via the onboard antenna 257 in FIG. 2B) remotefrom the drone. In some embodiments, a switch or the control unitlocated elsewhere on the drone (e.g., the central portion 115 in FIG.1A) may activate the motor assembly 567, such as by directing powerthereto (e.g., via the conductive strip 575 in FIG. 5A).

FIG. 6A is a perspective view of a weight distribution apparatus 600 foradjusting a center of mass of a drone (e.g., 10 in FIGS. 1A and 3)according to various embodiments. With reference to FIGS. 1A-6A, invarious embodiments, the weight distribution apparatus 600 may include abalance track 640 for holding one or more repositionable weights 650 inone or more of a plurality of weight-balance fixation positions 645. Thebalance track 640 may be part of, attached to, or disposed on one of theextension arms 130 that supports a single one of the air propulsionunits 120 of a drone (e.g., 10 in FIGS. 1A and 3). The balance track640, as well as the extension arm 130, may extend laterally from thecentral region (e.g., 115 in FIG. 1A) of the drone toward the airpropulsion unit 120. The balance track 640 may be one of multiple suchbalance tracks, each extending laterally on separate extension arms 130(e.g., see FIGS. 1A and 3).

In various embodiments, the repositionable weights 650 may be removablysecured to at least one of the weight-balance fixation positions 645.For example, one of the repositionable weights 650 is shown secured in afirst position (indicated by the arrow extending from a circle labeled“1”). The first position may be selected for the one of therepositionable weights 650 to balance the drone based on a particularpayload configuration. The one of the repositionable weights 650 may berepositioned to a second position (indicated by the arrow extending froma circle labeled “2”). In the second position, the one of therepositionable weights 650 moves the center of mass of the overall droneaway from the central portion (e.g., 115 in FIGS. 1A and 3) and toward adistal end 139 of the extension arm 130. The plurality of weight-balancefixation positions 645 may be evenly distributed along a longitudinalextent of the balance track 640 for providing a linear adjustment whenmoving one of the repositionable weights 650. Alternatively, theplurality of weight-balance fixation positions 645 may have an unevendistribution, such as an increasing or decreasing spacing along thelongitudinal extent of the balance track 640. In addition, the balancetrack 640 may be one of multiple such balance tracks, each extendinglaterally on separate extension arms 130 (e.g., see FIGS. 1A and 3).

In various embodiments, the repositionable weights 650 may each includean energy cell. In this way, an onboard power source may double as partof the weight distribution apparatus 600. The conductive strip 575(similar to that described with reference to FIGS. 5A and 5B) may extendalong the balance track 640 so that the repositionable weights 650 maybe electrically coupled to the conductive strip 575 in any of theplurality of weight-balance fixation positions 645.

FIG. 6B is a cross-sectional view at cross-section 6B-6B in FIG. 6A,illustrating the balance track 640 on the extension arm 130, supportingone of the plurality of repositionable weights 650 according to someembodiments. With reference to FIGS. 1A-6B, the repositionable weights650 may include a fastening mechanism 655 for removably securing eachone of the plurality of repositionable weights 650 to the balance track640. The fastening mechanism 655 may extend through an aperture forminga particular one of the plurality of weight-balance fixation positions(labeled as “645”). This may allow the fastening mechanism 655 to reachthrough the extension arm 130 and engage a back-plate element 651designed to receive and hold the fastening mechanism 655 once securedtherein. The back-plate element 651 may include a recess for matinglyreceiving and holding the fastening mechanism 655 therein. For example,the fastening mechanism 655 may include a threaded shaft that matches athreaded recess or aperture in the back-plate element 651. A variationof the back-plate element 651 may include a nut and washer arrangementthat mates to a threaded shaft of the fastening mechanism 655.Alternatively, the fastening mechanism 655 and the back-plate element651 may include magnetic elements for holding together the fasteningmechanism and the back-plate element 651. In addition, the back-plateelement 651 may be configured in more than one size or weight so thatthe back-plate element 651 may add to the weight of the repositionableweights 650.

FIG. 7 is a top view of a drone 17 that includes a weight distributionapparatus 700 for adjusting a center of mass according to variousembodiments. In various embodiments, the drone 17 and/or componentsthereof may generally correspond to the drone 10 (e.g., FIGS. 1A and 3).With reference to FIGS. 1A-7, the weight distribution apparatus 700 mayinclude balance tracks 740 extending laterally from a central region ofthe drone 17. The balance track 740 may be configured to receive arepositionable weight 750 for adjusting the center of mass of the drone17. The drone 17 may include four propellers 125 (i.e., a quad-copter)driven by air propulsion units (e.g., 120 in FIG. 1A). Extension armssupporting the propellers 125 may form the balance tracks 740 (e.g., 130in FIGS. 1A-2B and 4-6B). The balance tracks 740 include a plurality ofweight-balance fixation positions distributed continuously along an axis735 common to and extending longitudinally across two opposed extensionarms. Marks, stops, apertures, or other demarcations in or on thebalance tracks 740 may establish particular ones of the plurality ofweight-balance fixation position. In such embodiments, a repositionableweight 750 may be repositionable (e.g., by sliding or being removed andre-secured in another position) along the balance track 740 from oneextension arm (e.g., one of the extension arms on the right side of FIG.7) to the opposed extension arm (e.g., one of the other extension armson the left side of FIG. 7) along the axis 735.

Two of the axes 735 may intersect at a non-orthogonal angle X. Thenon-orthogonal angle X may be larger or smaller as appropriate foraerodynamics, payload configuration, or other considerations. Inalternative embodiments, the extension arms forming the balance tracks740 may change shape or be moveable. For example, the extension armsforming the balance tracks 740 may retract or extend in order to shortenor lengthen the balance tracks 740, and thus change the position of oneor more of the repositionable weights 750. As a further example, theextension arms forming the balance tracks 740 may pivot, changing thenon-orthogonal angle X. The drone may be configured to operate in afirst flight mode in which the balance tracks 740 are set to a firstlength and/or a first angle, and in a second flight mode in which thebalance tracks 740 are set to a second length and/or a second angle.

FIG. 8 is a top view of a three-rotor drone 18 that includes a weightdistribution apparatus 800 for adjusting a center of mass according tovarious embodiments. In various embodiments, the drone 18 and/orcomponents thereof may generally correspond to the drone 10 (e.g., FIGS.1A and 3). With reference to FIGS. 1A-8, the weight distributionapparatus 800 may include three balance tracks 840 extending laterallyfrom a central region of the drone 18. Each of the balance tracks 840extend in a different direction. The balance track 840 may be configuredto receive a repositionable weight 850 for adjusting the center of mass.The drone 18 may include three propellers 125 (i.e., a tri-copter)driven by air propulsion units (e.g., 120 in FIG. 1A). Extension armssupporting the propellers 125 may form the balance tracks 840 (e.g., 130in FIGS. 1A-2B and 4-6B). The three balance tracks 840 may include aplurality of weight-balance fixation positions distributed along an axis835 extending longitudinally along each extension arm. Therepositionable weight 850 is repositionable (e.g., by sliding or beingremoved and re-secured in another position) along any one of the threebalance tracks 840, moving to the central region in order to change fromone of the balance tracks 840 to another one of the balance tracks 840.

FIG. 9 is a top view of an eight-rotor drone 19 that includes a weightdistribution apparatus 900 for adjusting a center of mass according tovarious embodiments. In various embodiments, the drone 19 and/orcomponents thereof may generally correspond to the drone 10 (e.g., FIGS.1A and 3). With reference to FIGS. 1A-9, the weight distributionapparatus 900 may include two sets of four balance tracks 941, 942extending laterally from a central region of the drone 19. The two setsof four balance tracks 941, 942 may be configured to receive arepositionable weight 950 for adjusting the center of mass. The drone 19may include eight propellers 125 (i.e., an octo-copter) driven by airpropulsion units (e.g., 120 in FIG. 1A). Extension arms supporting thepropellers 125 may form the two sets of four balance tracks 941, 942(e.g., 130 in FIGS. 1A-2B and 4-6B). The eight propellers 125 may bedivided into two groups corresponding to the two sets of four balancetracks 941, 942, with each group at a different height so the propellers125 do not collide. The two sets of four balance tracks 941, 942 includea plurality of weight-balance fixation positions distributedcontinuously along an axis extending longitudinally along each extensionarm. The repositionable weight 950 may be repositionable (e.g., bysliding or being removed and re-secured in another position) along anyone of the two sets of four balance tracks 941, 942.

FIG. 10 is a top view of another configuration of a quad-rotor drone 20that includes a weight distribution apparatus 1000 for adjusting acenter of mass according to various embodiments. In various embodiments,the drone 20 and/or components thereof may generally correspond to thedrone 10 (e.g., FIGS. 1A and 3). With reference to FIGS. 1A-10, theweight distribution apparatus 1000 may include balance tracks 1040extending laterally from a central region 1015 of the drone 20. Thebalance track 1040 may be configured to receive a repositionable weight1050 for adjusting the center of mass. The drone 20 may include fourpropellers 125 (i.e., a quad-copter) driven by air propulsion units(e.g., 120 in FIG. 1A). Extension arms supporting the propellers 125 mayform the balance tracks 1040 (e.g., 130 in FIGS. 1A-2B and 4-6B). Pairsof the balance tracks 1040 extend away from one another and the centralregion 1015 of the drone 20 along an axis 1035 common to both balancetracks 1040. In addition, the balance tracks 1040 form an H-framestructure. In this way, a first pair of the balance tracks 1040 alongwith a corresponding first pair of the axis 1035 (e.g., on the rightside in FIG. 10) extend parallel to a second pair of the balance tracks1040 and a corresponding second pair of the axis 1035 (e.g., on the leftside in FIG. 10). The balance tracks 1040 include a plurality ofweight-balance fixation positions distributed continuously along each ofthe axes 1035. In this way, the repositionable weight 1050 may berepositionable (e.g., by sliding or being removed and re-secured inanother position) along the balance track 1040.

With reference to FIGS. 1A-10, in various embodiments the repositionableweights (e.g., 150, 250, 450, 550, 650, 750, 850, 950, 1050) may befluid weights formed by a fluid or semi-solid substance that can bepumped or redistributed within a piping system in order to adjust thecenter of gravity of the drone. In such embodiments, the balance tracksmay be in the form of tubing or an inner conduit for conveying the fluidabout the frame. A pump (not shown) may move (i.e., reposition) some orall of the fluid in order to redistribute weight along a particularbalance track. For example, the pump may be configured to push the fluidtoward an inner part of the balance track, an outer part of the balancetrack, somewhere in-between, or evenly distributed across the extent ofthe balance track. Each balance track may have a separate pump ormultiple balance tracks may share a pump. A semi-solid substance mayinclude a liquid or gas and numerous solid elements, such as pellets orball bearings, contained within. For example, a distribution of ballbearings may be changed using pressurized air. Alternatively, therepositionable weights may include such numerous small solid elements(e.g., ball bearings) that are moved with magnetic forces or mechanicalelements.

FIG. 11 is a perspective view of a drone 21 that includes a weightdistribution apparatus 1100 for adjusting a center of mass according tovarious embodiments. In various embodiments, the drone 21 and/orcomponents thereof may generally correspond to the drone 10 (e.g., FIGS.1A and 3). With reference to FIGS. 1A-11, in various embodiments, theweight distribution apparatus 1100 may include extension arms 1130 thatare separate from balance tracks 1140. The balance tracks 1140 extendlaterally from a central region 1115 of the drone 21. The balance tracks1140 may be configured to receive a repositionable weight 1150 foradjusting the center of mass. The drone 21 may include four propellers125 (i.e., a quad-copter) driven by air propulsion units (e.g., 120 inFIG. 1A). The extension arms 1130 support the propellers 125. Thebalance tracks 1140 also include a plurality of weight-balance fixationpositions distributed continuously along each axis 1145 common to andextending longitudinally across two opposed extension arms. One or moreof the repositionable weights 1150 may be removably secured along one ormore of the balance tracks 1140. Each of the repositionable weights 1150may be disposed a different distance from the central region 1115 of thedrone 21 in order to achieve a desired balance adjustment. As anoptional alternative, the balance tracks 1140 may be configured torotate about a vertical central axis or central region 1115 of the drone21 (“up” or “down” relative to the perspective view in FIG. 11).

FIG. 12 is a perspective view of a drone 22 that includes a weightdistribution apparatus 1200 for adjusting a center of mass according tovarious embodiments. In various embodiments, the drone 22 and/orcomponents thereof may generally correspond to the drone 10 (e.g., FIGS.1A and 3). With reference to FIGS. 1A-12, in such embodiments, theweight distribution apparatus 1200 may include balance tracks 1240extending laterally from a central region 1215 of the drone 21. Thebalance tracks 1240 may be configured to receive a repositionable weight1250 for adjusting the center of mass. In addition, the balance tracks1240 may change length (i.e., retract or extend) for repositioning therepositionable weight 1250. The drone 21 may include four propellers 125driven by air propulsion units (e.g., 120 in FIG. 1A). Extension arms1230 supporting the propellers 125 are separate from the balance tracks1240. The balance tracks 1240 include a plurality of weight-balancefixation positions corresponding to different lengths of the balancetracks 1240, which may be changed. In this embodiment, the length ofeach balance track 1240, along an axis 1245 extending away from thecentral region 1215, may be shortened or lengthened in order to changethe position of the repositionable weight 1250. Each of therepositionable weights 1250 may be retracted or extended to a differentrelative distance from the central region 1215 of the drone 21 in orderto achieve a desired balance adjustment. As an optional alternative, thebalance tracks 1240 may be configured to rotate about a vertical centralaxis or central region 1215 of the drone 21 (“up” or “down” relative tothe perspective view in FIG. 12).

FIG. 13A is a perspective view of a drone 23 that includes a weightdistribution apparatus 1300 for adjusting a center of mass according tovarious embodiments. FIG. 13B is a side view of the drone in FIG. 13A.In various embodiments, the drone 23 and/or components thereof maygenerally correspond to the drone 10 (e.g., FIGS. 1A and 3). Withreference to FIGS. 1A-13B, in various embodiments, the weightdistribution apparatus 1300 may include balance tracks 1340 extendinglaterally from a central region 1315 of the drone 23. The balance track1340 may be configured to receive a repositionable weight 1350 foradjusting the center of mass. The drone 23 may include eight propellers1325 (i.e., an octo-copter) driven by air propulsion units 1320.Extension arms 1330 form an oblong frame structure supporting thepropellers 1325 on an inside of the frame structure and the balancetracks 1340 along the outside of the frame structure. The balance tracks1340 extend away from the central region 1315 and form an H-framestructure in this embodiment, with a first one of the balance tracks1340 (e.g., on the top left in FIG. 13A) extending parallel to a secondone of the balance tracks 1340 (e.g., on the bottom right in FIG. 13A).

The balance tracks 1340 may be formed as a loop that may be continuous,segmented with gaps, or linked together like chain links. In addition,the balance tracks 1340 may form a thick flat band, a more bulky tread(e.g., a tank tread), a combination thereof, or another form. Thebalance tracks 1340 may be configured to circulate around the extensionarms 1330, which changes a position of one or more of the repositionableweights 1350. One or more rotational supports 1345 (see FIG. 13B) may bemotorized for rotating the balance track 1340 supported thereon. Inaddition, an onboard processor (e.g., located in the central region1315) may control the motorized rotation of the rotational supports1345. In this embodiment, the processor may control the rotation of eachof the balance tracks 1340 to change one or more of the repositionableweights 1350 into a different one the plurality of weight-balancefixation positions for balancing the drone 23.

The repositionable weights 1350 may be removably secured to a surface ofthe balance track 1340 (e.g., facing outwardly or facing the rotationalsupports 1345), such as with a fastening mechanism (e.g., 655 in FIG.6). This enables a position of the repositionable weight 1350 on thebalance track 1340 to be changed or one or more repositionable weights1350 removed (e.g., dropped) or added. Alternatively, the repositionableweights 1350 may be embedded in the balance track 1340, such as betweenlayers.

Optionally, movement of the drone 23 when landed may be provided usingthe balance tracks 1340 like tank treads. In such embodiments, thebalance tracks 1340 may provide direct engagement with a surface, likethe ground or a wall, for movement there along. When used for groundmovement, the rotation of the balance tracks 1340 may leave therepositionable weights 1350 in an unbalanced position. Thus, prior to orafter lift-off, the processor may activate one or more actuators to movethe repositionable weights 1350 into a more desirable one of theplurality of weight-balance positions to achieve a desired balanceadjustment. In addition, the repositioning of the repositionable weights1350 for repositioning the center of mass of the drone 23 may beperformed in stages. For example, a preliminary adjustment may beperformed before lift-off and a secondary adjustment may be performedafter lift-off.

FIG. 14A illustrates a method 1400 for adjusting a center of mass of adrone (e.g., 10 in FIGS. 1A and 3 and 17-23 in FIGS. 7-13B) using aweight distribution apparatus (e.g., 100, 200, 400, 500, 600, 700, 800,900, 1000, 1100, 1200, 1300 in FIGS. 1-13B) according to variousembodiments. With reference to FIGS. 1-14A, operations of the method1400 may be performed by a drone control unit (e.g., 255 in FIGS. 2B and3) or other computing device, and one or more actuators (e.g., motorassembly 567 in FIG. 5B) for changing the weight-balance fixationposition of one or more repositionable weights (e.g., 550 in FIGS. 5Aand 5B).

In block 1410, the processor (e.g., the processor 320 in the controlunit 255 or processor 302 in the remote communication device 300) mayreceive a weight-distribution input (e.g., via the bi-directionalwireless link 355) relating to balancing the drone. Theweight-distribution input may be received from a remote source, such asthrough wireless communications (e.g., via an onboard antenna 257), froman onboard sensor (e.g., via input module 340), from onboard components(e.g., via the input module 340 using the same or a different input portas the onboard sensor), or manually from a user or operator of thedrone. For example, the weight-distribution input may be an activationsignal sent from the operator (e.g., through a remote user interface onthe remote communication device 300 or through a user interface on thedrone). The weight-distribution input may include raw data, such as oneor more values corresponding to rotational forces in a pitch, yaw, orroll direction from existing imbalances. Alternatively, theweight-distribution input may include processed data indicating one ofthe plurality of weight-balance fixation positions at which one or moreof the repositionable weights should be in order to achieve a desiredbalance adjustment for the drone, such as based on current payloadpositions. As a further alternative, the weight-distribution input mayinclude a combination of raw and processed data.

The processor may receive the weight-distribution input in response toan initial or changed weight-distribution balance profile for the drone.In addition, changes to the weight-distribution balance profile thatgenerate a new weight-distribution input may result from the release,addition, or repositioning of payloads. In this way, theweight-distribution input may be received before the drone takes flight,during a flight from one location to another (e.g., a mid-airdrop-off/pick-up of payload), after landing but before a subsequentflight, or other suitable time. Alternatively, the processor may receivethe weight-distribution input during flight (e.g., just after take-off)in order to make refinements or any needed adjustments to theweight-distribution balance profile under real flight conditions (i.e.,an active system making dynamic adjustments). Mid-air adjustments may beused not only to adjust for weight of an added or released payload, butmay also adjust for changes in aerodynamic profile, shifting of payloador payload contents, consumption of fuel during the flight, and/orchanging external forces, such as turbulence (e.g., attitude adjustmentas part of flight control) or weather conditions (e.g., precipitation,wind, etc.). In this way, the processor may provide an active systemthat continually makes adjustments for weight and balance as needed.

In block 1420, a processor (e.g., processor 320 in the control unit 255or processor 302 in the remote communication device 300) may determine aweight-distribution balance profile for the drone. The processor maydetermine the weight-distribution balance profile at any time, includingbefore the drone lifts-off, after lift-off, mid-fight, or after landing.The weight-distribution balance profile may include appropriate balanceadjustments needed to balance the airframe in view of the receivedweight-distribution input. For example, the processor may access amemory (e.g., memory 321) in which the current positions of anyrepositionable weights are stored. In addition, based on theweight-distribution input received in block 1410, the processor maydetermine in which one(s) of the plurality of weight-balance fixationpositions one or more repositionable weights should be positioned inorder to achieve the desired balance adjustment for the drone. Forexample, received raw data may reflect a rotational force imbalance inone or more of pitch, yaw, or roll rotational directions. Based on therotational force imbalance, the processor may determine how therepositionable weights should be positioned in order to achieve balanceand eliminate the rotational force imbalance. Thus, comparing thecurrent weight-balance fixation positions to the weight-balance fixationpositions needed for balance, the processor may determine whether any ofthe repositionable weights need to be moved to balance the drone. Inaddition, the processor may determine the activation signals needed toactivate an actuator to move one or more of the repositionable weightsto the appropriate positions for achieving the desired balanceadjustment. Alternatively, the processor may receive manual controls,from an operator, that include or translate into the activation signals.

In determination block 1430, the processor may determine whether any ofthe repositionable weights should be repositioned in order to implementthe weight-distribution balance profile to achieve the desired balanceadjustment for the drone. In response to determining that at least oneof the repositionable weights needs to be repositioned in order toimplement the weight-distribution balance profile (i.e., determinationblock 1430=“Yes”), the processor may cause an actuator to reposition atleast one of the repositionable weights in block 1440. Repositioning therepositionable weight may include moving the repositionable weight alonga balance track, changing a length of a balance track, and/or rotatingthe balance track as described. Alternatively, repositioning therepositionable weight may include releasing the repositionable weightfor removal (e.g., activating an actuator allowing the repositionableweight to be removed or separate from the drone, such as dropping to theground). In response to determining that none of the repositionableweights needs to be repositioned in order to implement theweight-distribution balance profile (i.e., determination block1430=“No”), the control unit may repeat the operations of the method1400, waiting to receive further weight-distribution inputs in block1410.

In block 1440, the processor may cause one or more actuators toreposition one or more repositionable weights according to theweight-distribution balance profile. For example, the processor maycause an actuator (e.g., motor assembly 567) to move or release arepositionable weight (e.g., 150, 250, 450, 550, 650, 750, 850, 950,1050, 1150, 1250, 1350). In various embodiments, the actuator may movethe repositionable weight along a balance track (e.g., 140, 240, 440,540, 640, 740, 840, 941, 942, 1040, 1140, 1240, 1340), change a lengthof the balance track, and/or rotate the balance track to reposition therepositionable weight. The processor may achieve a desired new positionfor the repositionable weight by activating the actuator(s) (e.g., motorassembly 567) for a determined time sufficient to reach the desired newposition. Alternatively, the processor may start the actuator(s) andawait sensor feedback indicating the repositionable weight has reachedthe desired new position or that the drone is now balanced. As a furtheralternative, the start and stop of actuators may be controlled remotely(e.g., through wireless communications). For example, after theprocessor causes the actuator to start moving, following receipt ofremote instructions to do so, the processor may await further remoteinstructions to stop movement caused by the actuator. The control unitmay repeat the operations of the method 1400 following the trigger ofthe actuator(s) in block 1440, receiving further weight-distributioninputs in block 1410.

FIG. 14B illustrates an alternative method 1450 for adjusting a centerof mass of a drone (e.g., 10 in FIGS. 1A and 3 and 17-23 in FIGS. 7-13B)using a weight distribution apparatus (e.g., 100, 200, 400, 500, 600,700, 800, 900, 1000, 1100, 1200, 1300 in FIGS. 1-13B) according tovarious embodiments. With reference to FIGS. 1-14A, operations of themethod 1450 may be performed by a drone control unit (e.g., 255 in FIGS.2B and 3) or other computing device, and one or more actuators (e.g.,motor assembly 567 in FIG. 5B) for changing the weight-balance fixationposition of one or more repositionable weights (e.g., 550 in FIGS. 5Aand 5B).

In the method 1450, the processor (e.g., processor 320 in the controlunit 255 or processor 302 in the remote communication device 300) mayperform the operations of blocks 1410-1430 as described for likenumbered blocks of the method 1400. In block 1452, the processor mayoutput a signal for repositioning the repositionable weight(s) accordingto weight-distribution balance profile. The output signal may cause anactuator to operate as described with regard to the method 1450, orcommunicate information to another processor or device (onboard and/orremote from the drone). Information communicated by the output signalmay be stored (e.g., in memory) and/or used immediately. For example, anoutput signal may cause an indicator to indicate that a repositionableweight should be repositioned. The indicator may provide a visualindication (e.g., a diode that lights or a display screen presentinginformation), an audible indication (e.g., a sound or audibleinstructions), vibrations, and/or another indication. Indicationsprovided by the indicator may be relatively simple, such as by having alight turn on or off, or provided by sounding an alarm. Indicationsprovided by the indicator may alternatively or additionally provide moredetailed information, such as information that may inform an operatorabout how to reposition the weight(s) according to weight-distributionbalance profile. For example, the indicator may indicate that arepositionable weight should be moved, added, or removed. Similarly, theindicator may indicate that a length of a balance track should bechanged and/or the balance track rotated. In embodiments in whichinformation is sent in a data signal to another processor, the datasignal may include information for the other processor to cause theindicator to inform or to otherwise instruct an operator about how toreposition the weight(s) according to weight-distribution balanceprofile. For example, a remote user control component (e.g., remotecommunication device 300) may receive the data signal and activate aremote indicator that conveys information to a user.

In some embodiments, the processor may output the signal (e.g., via theoutput module 345 or the onboard antenna 257 and the bi-directionalwireless link 355) when moving around repositionable weights alone willnot achieve balance. For example, the processor cause the indicator todisplay a message to an operator (e.g., on an onboard or remote display)indicating that one or more repositionable weights need to be added toand/or removed from the drone in order to achieve the desired balanceadjustment.

The output provided by the drone processor in block 1452 may also be anoutput to another processor (either onboard or remote from the drone) toenable or prompt that other processor to perform further adjustments tothe weight-distribution balance profile. For example, the output may beto a processor on the drone that controls an actuator that is configuredto move the repositionable weights. As another example, the output maybe to a processor on the ground, such as a service or support robot ormachine on or near a drone launch pad, which may be configured toautomatically adjust the position of the repositionable weights inresponse to the output signal. As a further example, the output may beto a processor of a packaging and handling facility that is configuredto assemble a payload package based on information contained within theoutput signal before the payload is delivered to the drone for pickup.

The control unit may repeat the operations of the method 1450 followingthe output in block 1452, receiving further weight-distribution inputsin block 1410.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the steps of the various embodiments must be performed inthe order presented. As will be appreciated by one of skill in the artthe order of operations in the foregoing embodiments may be performed inany order. Words such as “thereafter,” “then,” “next,” etc. are notintended to limit the order of the operations; these words are used toguide the reader through the description of the methods. Further, anyreference to claim elements in the singular, for example, using thearticles “a,” “an” or “the” is not to be construed as limiting theelement to the singular.

The various illustrative logical blocks, modules, circuits, andalgorithm operations described in connection with the embodimentsdisclosed herein may be implemented as electronic hardware, computersoftware, or combinations of both. To clearly illustrate thisinterchangeability of hardware and software, various illustrativecomponents, blocks, modules, circuits, and operations have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the claims.

The hardware used to implement the various illustrative logics, logicalblocks, modules, and circuits described in connection with the aspectsdisclosed herein may be implemented or performed with a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general-purpose processor maybe a microprocessor, but, in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of receiver smartobjects, e.g., a combination of a DSP and a microprocessor, a pluralityof microprocessors, one or more microprocessors in conjunction with aDSP core, or any other such configuration. Alternatively, someoperations or methods may be performed by circuitry that is specific toa given function.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored as one or moreinstructions or code on a non-transitory computer-readable storagemedium or non-transitory processor-readable storage medium. Theoperations of a method or algorithm disclosed herein may be embodied ina processor-executable software module, which may reside on anon-transitory computer-readable or processor-readable storage medium.Non-transitory computer-readable or processor-readable storage media maybe any storage media that may be accessed by a computer or a processor.By way of example but not limitation, such non-transitorycomputer-readable or processor-readable storage media may include RAM,ROM, EEPROM, FLASH memory, CD-ROM or other optical disk storage,magnetic disk storage or other magnetic storage smart objects, or anyother medium that may be used to store desired program code in the formof instructions or data structures and that may be accessed by acomputer. Disk and disc, as used herein, includes compact disc (CD),laser disc, optical disc, digital versatile disc (DVD), floppy disk, andblu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveare also included within the scope of non-transitory computer-readableand processor-readable media. Additionally, the operations of a methodor algorithm may reside as one or any combination or set of codes and/orinstructions on a non-transitory processor-readable storage mediumand/or computer-readable storage medium, which may be incorporated intoa computer program product.

The preceding description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the claims. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the spirit or scopeof the claims. Thus, the present invention is not intended to be limitedto the embodiments shown herein but is to be accorded the widest scopeconsistent with the following claims and the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A weight distribution apparatus for adjusting acenter of mass of a drone, comprising: a first balance track extendingoutwardly from a central region of the drone, wherein the first balancetrack includes a plurality of predetermined weight-balance fixationpositions; and a repositionable weight configured to be secured at anyone of the plurality of predetermined weight-balance fixation positions.2. The weight distribution apparatus of claim 1, wherein therepositionable weight is slidable along the first balance track betweenthe plurality of predetermined weight-balance fixation positions.
 3. Theweight distribution apparatus of claim 1, wherein the first balancetrack is disposed on an extension arm of the drone, the extension armextending laterally from the central region, wherein a distal end of theextension arm supports an air propulsion unit.
 4. The weightdistribution apparatus of claim 3, wherein the repositionable weightwraps around at least a portion of the extension arm using an essentialstructural shape of the extension arm as the first balance track.
 5. Theweight distribution apparatus of claim 3, wherein the plurality ofpredetermined weight-balance fixation positions comprise a series ofapertures extending through the extension arm.
 6. The weightdistribution apparatus of claim 1, wherein the repositionable weight isconfigured to ride along guide elements included on the first balancetrack.
 7. The weight distribution apparatus of claim 1, wherein therepositionable weight includes an electronic component.
 8. The weightdistribution apparatus of claim 7, wherein the electronic componentcomprises at least one of an energy cell, an actuator, an indicator, acircuit element, a sensor, and a camera.
 9. The weight distributionapparatus of claim 7, further comprising: a control unit configured toactivate the electronic component, wherein the control unit is fixed tothe repositionable weight.
 10. The weight distribution apparatus ofclaim 7, further comprising: a control unit configured to activate theelectronic component, wherein the control unit is remote from therepositionable weight.
 11. The weight distribution apparatus of claim 7,further comprising a control unit configured to activate the electroniccomponent, wherein the control unit comprises: a radio frequencytransceiver, and a processor coupled to the radio frequency transceiverand configured with processor-executable instructions to activate amovement of the repositionable weight from a first one of the pluralityof predetermined weight-balance fixation positions to a second one ofthe plurality of predetermined weight-balance fixation positions inresponse to receiving an activation signal via the radio frequencytransceiver.
 12. The weight distribution apparatus of claim 1, whereinthe repositionable weight is removably secured to at least one of theplurality of predetermined weight-balance fixation positions.
 13. Theweight distribution apparatus of claim 12, wherein the plurality ofpredetermined weight-balance fixation positions are evenly distributedalong a longitudinal extent of the first balance track.
 14. The weightdistribution apparatus of claim 1, further comprising: a second balancetrack extending outwardly from the central region along a second axisthat is different from a first axis of the first balance track.
 15. Theweight distribution apparatus of claim 14, wherein the first axisintersects the second axis at a non-orthogonal angle.
 16. The weightdistribution apparatus of claim 14, further comprising: a third balancetrack extending away from the central region along a third axis that isdifferent from both the first axis and the second axis.
 17. The weightdistribution apparatus of claim 14, wherein the first axis is parallelto the second axis.
 18. The weight distribution apparatus of claim 14,wherein the first and second axes are not parallel to extension armssupporting rotors of the drone.
 19. The weight distribution apparatus ofclaim 1, wherein the first balance track is configured to change lengthfor changing the repositionable weight from a first one of the pluralityof predetermined weight-balance fixation positions to a second one ofthe plurality of predetermined weight-balance fixation positions. 20.The weight distribution apparatus of claim 1, wherein the first balancetrack is configured to rotate about a vertical central axis of thedrone.
 21. The weight distribution apparatus of claim 1, wherein thedrone is a multi-rotor helicopter.
 22. The weight distribution apparatusof claim 1, wherein in response to a change in a weight-distributionbalance profile of the drone, in which a payload is added to or removedfrom the drone, the plurality of weight-balance fixation positions arearranged such that repositioning of the repositionable weight to adifferent one of the plurality of predetermined weight-balance fixationpositions restores the weight-distribution balance profile.
 23. Theweight distribution apparatus of claim 1, wherein the plurality ofweight-balance fixation positions are arranged such that changing therepositionable weight from a first one of the plurality of predeterminedweight-balance fixation positions to a second one of the plurality ofpredetermined weight-balance fixation positions changes the center ofmass of the drone.
 24. A method of adjusting a center of mass of adrone, comprising: receiving, in a processor, a weight-distributioninput relating to balancing the drone, wherein a first balance trackextends outwardly from a central region of the drone and a firstrepositionable weight is configured to be secured at any one of aplurality of predetermined weight-balance fixation positions included inthe first balance track; determining, in the processor, aweight-distribution balance profile based on the weight-distributioninput; determining, in the processor, whether the first repositionableweight should be repositioned; outputting a signal from the processor toan actuator included on the drone, in response to determining that thefirst repositionable weight should be repositioned, for repositioningthe first repositionable weight according to the weight-distributionbalance profile; and changing, by the actuator, a position of the firstrepositionable weight on the first balance track according to thedetermined weight-distribution balance profile in response to receivingthe signal.
 25. The method of claim 24, wherein the first repositionableweight is an electronic component.
 26. The method of claim 25, whereinthe electronic component is at least one of an energy cell, theactuator, an indicator, a circuit element, a sensor, and a camera. 27.The method of claim 24, wherein the weight-distribution input isreceived from a remote source.
 28. The method of claim 24, wherein thesignal causes the actuator to release the first repositionable weightfor removal from the first balance track in order to conform to theweight-distribution balance profile.
 29. The method of claim 24, whereinthe signal causes the actuator to move the first repositionable weightalong the first balance track between the plurality of predeterminedweight-balance fixation positions.
 30. The method of claim 24, whereinthe signal causes the actuator to change a length of the first balancetrack in order to reposition the first repositionable weight from afirst one of the plurality of predetermined weight-balance fixationpositions to a second one of the plurality of predeterminedweight-balance fixation positions.
 31. The method of claim 24, whereinthe signal causes the actuator to rotate the first balance track about avertical central axis of the drone in order to change the firstrepositionable weight from a first one of the plurality of predeterminedweight-balance fixation positions to a second one of the plurality ofpredetermined weight-balance fixation positions.
 32. The method of claim24, wherein the drone is a multi-rotor helicopter.
 33. The method ofclaim 24, wherein the first repositionable weight is a payloadtemporarily carried by the drone.
 34. The method of claim 24, furthercomprising: repositioning the first repositionable weight to a differentone of the plurality of predetermined weight-balance fixation positionsin response to a change in the weight-distribution balance profile ofthe drone from a payload being added to or removed from the drone,wherein the plurality of predetermined weight-balance fixation positionsare arranged such that repositioning the first repositionable weightrestores the weight-distribution balance profile.
 35. The method ofclaim 24, further comprising: repositioning the first repositionableweight from a first one of the plurality of predetermined weight-balancefixation positions to a second one of the plurality of predeterminedweight-balance fixation positions, wherein the plurality ofpredetermined weight-balance fixation positions are arranged such thatrepositioning the first repositionable weight changes the center of massof the drone.
 36. The method of claim 24, wherein the signal causes anindicator to indicate that the first repositionable weight should berepositioned.
 37. The method of claim 36, wherein the signal causes theindicator to indicate that the first repositionable weight should bemoved along the first balance track between the plurality ofpredetermined weight-balance fixation positions.
 38. The method of claim36, wherein the signal causes the indicator to indicate that the firstrepositionable weight should be removed from the first balance track inorder to conform to the weight-distribution balance profile.
 39. Themethod of claim 36, wherein the signal causes the indicator to indicatethat a second repositionable weight should be added in order to conformto the weight-distribution balance profile.
 40. The method of claim 36,wherein the signal causes the indicator to indicate that a length of thefirst balance track should be changed in order to change the firstrepositionable weight from a first one of the plurality of predeterminedweight-balance fixation positions to a second one of the plurality ofpredetermined weight-balance fixation positions.
 41. The method of claim36, wherein the signal causes the indicator to indicate that the firstbalance track should be rotated about a vertical central axis of thedrone in order to change the first repositionable weight from a firstone of the plurality of predetermined weight-balance fixation positionsto a second one of the plurality of predetermined weight-balancefixation positions.
 42. The method of claim 36, wherein the indicator ison the drone.
 43. The method of claim 36, wherein the indicator isremote from the drone.
 44. A weight distribution apparatus for adjustinga center of mass of a drone, comprising: means for providing a pluralityof predetermined weight-balance fixation positions, wherein the meansfor providing the plurality of predetermined weight-balance fixationpositions comprises a first balance track extending outwardly from acentral region of the drone, wherein the first balance track includes aplurality of predetermined weight-balance fixation positions; a firstrepositionable weight configured to be secured at any one of theplurality of predetermined weight-balance fixation positions; means forreceiving a weight-distribution input relating to balancing the drone;means for determining a weight-distribution balance profile based on theweight-distribution input; means for outputting a signal, in response todetermining the weight-distribution balance profile, to reposition thefirst repositionable weight according to the weight-distribution balanceprofile; and means for changing a position of the first repositionableweight on the first balance track according to the determinedweight-distribution balance profile in response to receiving the signal.45. The weight distribution apparatus of claim 7, wherein therepositionable weight is configured to perform a function using theelectronic component in addition to adjusting the center of mass of thedrone.
 46. The method of claim 24, wherein the repositionable weight isconfigured to perform a function using the electronic component inaddition to adjusting the center of mass of the drone.
 47. The weightdistribution apparatus of claim 44, wherein the repositionable weight isconfigured to perform a function using the electronic component inaddition to adjusting the center of mass of the drone.